﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace H02
{
    class Program
    {
        static void Main(string[] args)
        {
            static void Main(string[] args)
            {
                Console.WriteLine("请输入一个数");
                int i = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine(FB(i));
            }
            static int FB(int i)
            {
                return i <= 1 ? i : FB(i - 1) + FB(i - 2);
            }

        }
    }
}
